Vapor deposition mask and method for producing electronic device

Abstract

The purpose of the present invention is to provide: a vapor deposition mask with which a vapor-deposited film having excellent pattern dimensions can be formed; and a method for producing an electronic device using the vapor deposition mask. This vapor deposition mask has a first surface and a second surface on the reverse side from the first surface, and has a plurality of openings piercing from the first surface to the second surface. The vapor deposition mask is characterized in that the openings have sidewall surfaces having ridges formed thereon which extend from the first surface side to the second surface side and that the proportion of the projection of the ridges to the opening width of the openings is 0.001-0.018.

Description

Evaporation mask and method for manufacturing electronic device

[0001] The present invention relates to a deposition mask and a method for manufacturing an electronic device.

[0002] For example, a deposition mask is known that is used to paint three colors, RGB, in the production of organic EL displays.

[0003] Patent Document 1 describes a deposition mask in which a mask pattern is formed on a silicon layer. It discloses that the mask pattern is formed by etching. Patent Document 2 describes a deposition mask having a large number of pixel openings. It discloses that the pixel openings are formed by etching.

[0004] Korean Patent No. 10-2358269 Japanese Patent Publication No. 2022-175925

[0005] The uneven shape of the sidewall surface of the opening causes deposition material to accumulate on the sidewall surface, resulting in a problem of deterioration in the pattern dimensions of the deposited film.

[0006] An object of the present invention is to provide a deposition mask capable of forming a deposition film having excellent pattern dimensions, and a method for manufacturing an electronic device using the deposition mask.

[0007] The vapor deposition mask of the present embodiment has a first surface and a second surface opposite to the first surface, and is formed with a plurality of openings penetrating between the first surface and the second surface, wherein a protrusion portion extending from the first surface side to the second surface side is formed on a side wall surface of the opening, and a protrusion ratio of the protrusion portion to the opening width of the opening is 0.001 or more and 0.018 or less.

[0008] According to the present invention, by controlling the protrusion ratio of the protrusions formed on the sidewall surfaces of the openings in the deposition mask, a deposition film having excellent pattern dimensions can be stably formed. Furthermore, the frequency of cleaning the deposition mask can be reduced, facilitating quality control of the deposition mask. Furthermore, the occurrence of clogging of the openings can be reduced, thereby extending the life of the deposition mask.

[0009] FIG. 4A is a cross-sectional view showing an example of a deposition mask according to the present embodiment; FIG. 4B is an enlarged plan view of an opening; and FIG. 4C is an enlarged front view of a sidewall surface that appears when the opening is cut. FIG. 4A is an SEM image showing a standard for measuring the protrusion dimension of a protrusion portion, and FIG. 4B is a schematic diagram thereof. FIG. 5A is an SEM photograph showing an enlarged portion of an opening, and FIG. 5B is a schematic diagram thereof. FIGS. 6A to 6E are schematic diagrams for explaining a method for calculating an opening width. FIG. 7A is an SEM image of a sidewall surface of an opening, and FIG. 7B is a schematic diagram thereof. An image diagram showing how a deposition material is deposited on the sidewall surface of an opening. FIG. 4B is a process diagram showing an example of a method for manufacturing a deposition mask according to the present embodiment; and FIG. 4C is a process diagram showing an example of a method for manufacturing a deposition mask according to the present embodiment. FIG. 4C is a cross-sectional view showing a method for manufacturing an electronic device that uses the deposition mask according to the present embodiment. FIG. 4D is a cross-sectional view showing an example of a deposition mask according to another embodiment. FIG. 4E is a cross-sectional view showing an example of a deposition mask according to another embodiment.

[0010] Hereinafter, embodiments will be described with reference to the drawings. However, the drawings are schematic or conceptual, and the dimensions and ratios of each drawing are not necessarily the same as those in reality. Furthermore, even when the same parts are shown between drawings, the dimensional relationships and ratios between them may be different. In particular, the embodiments shown below are illustrative of structures for embodying the technical idea of ​​the present invention, and do not specify the technical idea of ​​the present invention. In the following description, elements having the same function and configuration are designated by the same reference numerals, and redundant description will be omitted. Furthermore, the lower and upper limits of numerical ranges include a margin of error. Furthermore, the notation "to" is intended to include both the lower and upper limits.

[0011] <Background to the Invention> Vapor deposition masks used for painting different colors of RGB in the production of OLED displays are known, and there is a growing need for vapor deposition masks for painting different colors of RGB.

[0012] The deposition mask has a plurality of openings corresponding to the deposited film, and the accuracy of the openings in the deposition mask is important for improving the pattern dimensions of the deposited film.

[0013] The deposition mask is placed between the substrate and the deposition source, and the deposition material passes from the deposition source through the openings in the deposition mask and reaches the surface of the substrate. If the deposition material accumulates on the sidewalls of the openings, the opening width becomes narrower than the actual width, making it difficult to form a deposition film with excellent pattern dimensions.

[0014] 8 shows an image of the deposition material 12 being deposited on a sidewall surface 52 of an opening 51 formed in a membrane 50. In this way, the deposition material 12 being deposited on the sidewall surface 52 of the opening 51 creates a shadow effect.

[0015] During the fabrication of high-resolution OLED display devices, the shadow effect reduces the pattern size of the deposited film, which in turn affects device performance and becomes a limiting factor for the resolution of OLED microdisplay devices.

[0016] As a result of extensive research, the inventors have noticed that deposition material accumulates on the steps of vertical ridges (protrusions) that appear on the sidewall surfaces when openings are processed by dry etching, and have developed a deposition mask that can increase the pattern dimensions of the deposited film by optimizing the protrusion ratio of the protrusions to the opening width.

[0017] <Overview of deposition mask 1 according to the present embodiment> Fig. 1 is a cross-sectional view of a deposition mask 1 according to the present embodiment. Fig. 2 is an enlarged plan view of an opening. Fig. 3 is an enlarged front view of a sidewall surface appearing when cutting the opening. Fig. 4A is an SEM image showing a standard for measuring the protrusion dimension of a protrusion portion, and Fig. 4B is a schematic diagram thereof. Fig. 5A is an SEM photograph showing an enlarged portion of an opening, and Fig. 5B is a schematic diagram thereof. Fig. 7 is an SEM image of the sidewall surface of the opening.

[0018] The deposition mask 1 has a laminated structure of a membrane 2 and a support substrate 3. The membrane 2 is a substrate having a first surface 2a and a second surface 2b that face each other in the thickness direction, and the thickness of the membrane 2 is not limited, but is about 1 μm to 300 μm.

[0019] The outer peripheral shape of the membrane 2 is preferably a rectangular or disc-shaped wafer, and although there are no restrictions on the diameter (the length of one side in the case of a rectangle), it is preferably about 100 mm to 500 mm.

[0020] Although not limited thereto, the membrane 2 may be formed of a single layer or multiple layers. For example, the membrane 2 may be a SiN layer or a SiN layer / SiO ２ It is preferable that the insulating film is formed in a laminated structure of layers.

[0021] As shown in Fig. 1, a plurality of cell regions 4 are formed in the membrane 2. Between adjacent cell regions 4, there is a region (called a "boundary region 5") where no openings 8 are formed. In a plan view, the plurality of cell regions 4 are arranged in a matrix with the boundary region 5 interposed therebetween. A region where the plurality of cell regions 4 are gathered is called a cell array region 6. Between the cell array region 6 and the edge of the membrane 2 is a peripheral region 7.

[0022] 1, a plurality of openings 8 are formed in each cell region 4. The openings 8 penetrate the membrane 2 from the first surface 2a to the second surface 2b.

[0023] As shown in FIG. 11, the first surface 2 a is the front surface facing the deposition substrate 10 , and the second surface 2 b is the rear surface facing the deposition source 11 .

[0024] 1, the width of the opening 8 gradually narrows from the second surface 2b to the first surface 2a, for example. Therefore, the side wall surface 9 of the opening 8 is inclined.

[0025] The planar pattern of the openings 8 (the shape when viewed from directly above the membrane 2 toward the first surface 2a) is not limited, but examples include a rectangle (including a square), a polygon other than a rectangle, a circle, and an ellipse. All the openings 8 may have the same planar pattern, or some of them may have different patterns. The openings 8 may be arranged regularly, irregularly, or a mixture of regular and irregular arrangements.

[0026] Although there is no limitation on the width of the boundary region 5 between the cell regions 4, the width is about 1 mm to 10 mm when viewed from the first surface 2a side.

[0027] 1, a support substrate 3 is provided on the second surface 2b side of the membrane 2. The support substrate 3 is, for example, a silicon substrate. The thickness of the support substrate 3 is not limited, but is, for example, about 100 μm to 1000 μm.

[0028] As shown in FIG. 1 , the support substrate 3 is provided in the peripheral region 7 and the boundary region 5 on the second surface 2 b of the membrane 2. As such, the support substrate 3 is not provided in the cell region 4, which is open to both the first surface 2 a and the second surface 2 b. The support substrate 3 may be provided only in the peripheral region 7. The membrane 2 can be maintained in a taut state by the support substrate 3, eliminating the need for a tensioning process. The deposition mask 1 of this embodiment can also be closely attached to the deposition substrate 10 using an electrostatic chuck that utilizes electrostatic force. As shown in FIG. 1 , the support substrates 3 provided in the boundary region 5 and the peripheral region 7 all have the same height. However, for example, the height of the support substrate 3 provided in the boundary region 5 may be lower than the height of the support substrate 3 provided in the peripheral region 7. However, by making the heights uniform, greater strength can be maintained.

[0029] <Detailed Description of Opening 8 of Vapor Deposition Mask 1 in the Present Embodiment> As shown in the plan view of the opening 8 in Fig. 2 and the front view of the opening 8 obtained by cutting the opening 8 in Fig. 3 (both sides of the opening 8 are shown as cross sections), a plurality of protrusions 20 extending from the first surface 2a toward the second surface 2b are formed on a side wall surface 9 of the opening 8. In the present embodiment, the protrusions 20 may be referred to as "vertical stripes." Because the protrusions 20 protrude from the side wall surface 9 toward the inside of the opening 8, the side wall surface 9 has uneven steps as shown in Figs. 2 and 3 .

[0030] The height (length) of the protrusions 20 from the first surface 2a to the second surface 2b may be the same as or shorter than the height (length) from the first surface 2a to the second surface 2b. That is, the protrusions 20 may be interrupted midway as long as they are formed in the height region between the first surface 2a and the second surface 2b. However, it is preferable that the height of the protrusions 20 is the same as the height (length) from the first surface 2a to the second surface 2b. This allows the protrusions 20 to be continuous without interruption midway in the height direction between the first surface 2a and the second surface 2b, eliminating unevenness in the height direction or reducing the difference in unevenness, thereby reducing the accumulation of deposition material.

[0031] Furthermore, the shape of the protrusions 20 is not particularly limited, and may be curved, serpentine, or have a shape that changes midway (changing the extension direction midway), in addition to being formed linearly from the first surface 2a side to the second surface 2b side. However, the protrusions 20 are preferably linear. "Straight" does not mean a straight line in the strict sense, but allows for some variation. For example, without limitation, a shape can be considered linear if the extension direction changes within about 5 degrees with respect to the direction perpendicular to the height direction. By forming the protrusions 20 linearly, the area where the extension direction changes can be eliminated or reduced, thereby reducing the accumulation of deposition material.

[0032] The opening 8 shown in Fig. 2 is substantially polygonal, but may also be circular or elliptical. As shown in Fig. 2, the protrusions 20 are formed evenly around the periphery of the opening 8, but the formation density of the protrusions 20 may vary depending on the location on the side wall surface 9. For example, the formation density of the protrusions 20 may change from halfway along the height of the side wall surface 9.

[0033] [Method of Calculating Protrusion Dimension] Fig. 4A is an SEM photograph of the opening 8, and Fig. 4B is a schematic diagram thereof. The SEM (scanning electron microscope) image of the opening 8 was obtained using, for example, Regulus 8220 manufactured by Hitachi High-Technologies.

[0034] FIG. 5A is an enlarged photograph of the area surrounded by region A in the SEM photograph of FIG. 4A, and FIG. 5B is a schematic diagram thereof.

[0035] In the following, a case where the opening 8 has a substantially polygonal shape as shown in FIGS. 4A and 4B will be described.

[0036] As shown in Figures 4A and 4B, a straight reference line L1 is drawn on each side of the opening 8 so as to be in contact with the outside of the unevenness of the opening 8. At this time, as shown in Figures 5A and 5B, it is preferable to draw the reference line L1 so that it is in contact at multiple contact points B. Furthermore, the reference line L1 is drawn so that it is in contact at as many contact points B as possible, except for areas where the unevenness of the opening 8 has changed drastically or areas where the SEM image is unclear and the unevenness is difficult to distinguish.

[0037] Then, the reference line L1 was divided into, for example, three equal parts, and protrusion dimensions H1, H2, and H3 (hereinafter, sometimes referred to as "protrusion dimension H") of the protrusion portion 20 that protrudes from the central reference line L1 into the opening 8 were measured. The apex of each of the protrusion dimensions H1, H2, and H3 was determined to be the position that protrudes the most from the central reference line L1.

[0038] Then, the average protrusion dimension AveH of the protrusion dimensions H1, H2, and H3 of each protrusion 20 is calculated.

[0039] If the shape of the opening 8 is a circle or an ellipse, the reference line L1 is drawn in a curved line along the shape. The reference line is then divided into a plurality of parts, and one of the parts is used to determine the protrusion dimension of the protrusion.

[0040] In the above, the reference line L1 is divided into three equal parts to measure the protrusion dimension H of the protrusion 20, but dividing it into three equal parts is merely an example. Furthermore, the number of protrusions 20 measured from the reference line L1 is not limited, but can be approximately 2 to 50, preferably 30 or less, and more preferably 20 or less. Furthermore, it is preferable to measure two or more, preferably five or more. This improves the dimensional accuracy of the average protrusion dimension AveH of the protrusion 20. Furthermore, in this embodiment, a measurement error of ±10% or less, preferably ±5% or less, is acceptable for the average protrusion dimension AveH of the protrusion 20.

[0041] [Method for calculating opening width W1] As shown in Figures 1 and 3, for example, the opening 8 gradually narrows from the second surface 2b toward the first surface 2a, and the opening width varies depending on the measurement location. In this embodiment, the opening width W1 of the opening 8 is defined as the width on the first surface 2a side facing the deposition substrate 10.

[0042] The opening width W1 can be determined from an SEM image obtained using eCD-2 manufactured by KLA-Tencor.

[0043] The opening width W1 can be determined from the reference line L1 used to determine the protrusion dimension H of the protrusion 20. However, when attempting to determine the opening width W1 from the reference line L1, if the difference between the area enclosed by the reference line L1 and the area of ​​the opening 8 becomes large, this means that the deviation between the reference line L1 and the opening 8 becomes large, and the accuracy of calculating the opening width W1 is likely to decrease. For example, if the area difference is 10% or more, preferably 5% or more, it is desirable to calculate the opening width W1 using the following method.

[0044] That is, the longest distance among the distances between each vertex 8a of the opening 8 in FIG. 6 and the intersection 8c where the straight line L2 passing from the vertex 8a through the center O of the ellipse 14 intersects with the side 8b of the opening 8 is defined as the opening width W1.

[0045] 6A is a schematic diagram for explaining a method for calculating the opening width W1. In FIG. 6A, the opening 8 is substantially hexagonal. Therefore, there are six vertices 8a and six sides 8b of the opening 8 that appear on the first surface 2a. The sides 8b are regression lines. The regression line can be determined by the least squares method.

[0046] Next, an ellipse 14 is drawn that circumscribes each vertex 8a. The ellipse 14 includes a circle. Then, the center O of the ellipse 14 is found.

[0047] A straight line L2 passing through the center O is drawn from each vertex 8a, and an intersection 8c is found where the line L2 intersects with the side 8b of the opening 8. The distance between the vertex 8a and the intersection 8c is then calculated. In Figure 6A, there are a total of six vertices 8a, so six such distances are found from each vertex 8a, and the longest distance is taken as the opening width W1.

[0048] In Figure 6B, the opening 8 is triangular, in Figure 6C, the opening 8 is pentagonal, and Figures 6D and 6E show special shapes in which the polygon is distorted. In Figures 6B to 6E, white circles indicate vertices 8a, and black circles indicate intersections 8c. As explained in Figure 6A, an ellipse 14 circumscribing each vertex 8a is drawn, and the center O of the ellipse 14 is found. Then, a straight line L2 passing through the center O is drawn from each vertex 8a, and the intersection 8c where the straight line L2 intersects with the side 8b of the opening 8 is found. The distance between the vertex 8a and the intersection 8c is calculated, and the longest distance is defined as the opening width W1.

[0049] When drawing the ellipse 14, depending on the shape of the opening, it may be difficult to draw an ellipse 14 that circumscribes all of the vertices 8a. In this case, the ellipse 14 is drawn so that it circumscribes as many vertices 8a as possible, and for the vertices 8a that are not circumscribed, it is drawn so that the curve of the ellipse 14 is as close as possible to the ellipse 14. Also, it is acceptable for some of the ellipse 14 to be drawn so that it extends inside the opening 8.

[0050] [Method of Calculating Protrusion Ratio of Protrusions 20] As described above, the average protrusion dimension AveH of the protrusions 20 and the opening width W1 of the openings 8 are determined, and the protrusion ratio (average protrusion dimension AveH / opening width W1) R is calculated.

[0051] A small protrusion ratio R means that if the average protrusion dimension AveH of the protrusion streaks 20 is constant, the opening width W1 is large, or if the opening width W1 is constant, the average protrusion dimension AveH of the protrusion streaks 20 is small. On the other hand, a large protrusion ratio R means that if the average protrusion dimension AveH of the protrusion streaks 20 is constant, the opening width W1 is small, or if the opening width W1 is constant, the average protrusion dimension AveH of the protrusion streaks 20 is large. In this way, in the present embodiment, the protrusion ratio R can be controlled to fall within a predetermined range by adjusting one or both of the average protrusion dimension AveH and the opening width W1 of the protrusion streaks 20.

[0052] [Method of Calculating Taper Angle θ1 of Opening 8] In this embodiment, the taper angle θ1 of opening 8 is calculated as follows. That is, as shown in Fig. 3, a straight line is connected between an end of opening width W1 in the surface direction along first surface 2a and an end of opening width W2 in the surface direction along second surface 2b, and the inclination angle between this line and first surface 2a can be set as the taper angle θ1 of opening 8. The taper angle θ1 was calculated by measuring the length of an SEM image obtained using a Regulus 8220 manufactured by Hitachi High-Technologies.

[0053] <Regarding Characteristic Configuration of Opening Parameters in the Present Embodiment> The deposition mask 1 in the present embodiment is characterized in that: (1) a protrusion portion 20 is formed on the side wall surface 9 of the opening 8, extending from the first surface 2 a side toward the second surface 2 b side; and (2) a protrusion ratio R of the protrusion portion 20 to the opening width W1 of the opening 8 is 0.001 or more and 0.018 or less.

[0054] The protrusions 20 shown in (1) above result from the dry etching process used to form the openings 8. That is, the protrusions 20 are a processed shape specific to dry etching, and appear as vertical streaks in the height direction (vertical direction) of the openings 8.

[0055] The protrusions 20 cause deposition of the deposition material 12 as described in Fig. 8, resulting in poor deposition. The protrusions 20 are a processed shape specific to dry etching, but conventionally, the dimensions of the protrusions 20 have not been adjusted.

[0056] Therefore, in this embodiment, the protrusion ratio R of the protrusion 20 is specified so that the pattern width W3 of the vapor-deposited film 13 can be adjusted to 70% or more of the opening size (opening width W1).

[0057] The characteristics of the protrusion ratio R are shown in (2) above. That is, in this embodiment, by adjusting the protrusion ratio R of the protrusion portion 20 to the opening width W1 of the opening to 0.001 or more and 0.018 or less, the pattern width W3 of the vapor-deposited film 13 can be appropriately and easily adjusted to 70% or more of the opening size (opening width W1).

[0058] In this embodiment, the protrusion ratio R is more preferably 0.014 or less. This allows the pattern width W3 of the deposited film 13 to be appropriately and easily adjusted to 80% or more of the opening size (opening width W1), preferably 85% or more, and more preferably 90% or more. The lower limit of the protrusion ratio R is not limited, but is set to 0.001 or more, 0.002 or more, 0.003 or more, or 0.004 or more depending on the dry etching conditions.

[0059] Furthermore, by setting the protrusion ratio R to 0.001 or more, impurities contained in the deposition material (deposition particles) 12 from the deposition source 11 shown in FIG. 11 can be captured by the side wall surface 9 of the opening 8, thereby reducing the amount of impurities contained in the deposition film 13. That is, the particles scattered from the deposition source 11 toward the deposition substrate 10 contain impurities. Furthermore, because the deposition conditions are set so that the deposition particles 12 adhere to the surface of the deposition substrate 10 in a direction perpendicular to the surface, impurities that do not meet these conditions tend to scatter obliquely from the direction perpendicular to the surface of the deposition substrate 10. Therefore, by setting the protrusion ratio R not to zero, specifically to 0.001 or more, impurities can be more easily captured by the side wall surface 9.

[0060] In this embodiment, the average protrusion dimension AveH of the protrusions 20 is preferably 150 nm or less, more preferably 145 nm or less, and even more preferably 143.5 nm or less, which allows the protrusion ratio R of the protrusions 20 to the opening width W1 of the opening 8 to be appropriately and easily adjusted to be 0.001 or more and 0.018 or less.

[0061] In this embodiment, the maximum protrusion dimension of the protrusions 20 is preferably 200 nm or less, more preferably 185 nm or less, and even more preferably 181 nm or less. This eliminates excessively large protrusions 20, effectively suppressing deposition defects. Furthermore, the protrusion ratio R of the protrusions can be easily and appropriately adjusted to a range of 0.001 to 0.018.

[0062] In this embodiment, the opening width W1 is preferably 10 μm or less. Although there is no lower limit, it can be 1 μm or more. This satisfies the needs of the deposition mask 1 including the membrane 2. In particular, the opening width W1 needs to be further reduced for a deposition mask for separate RGB coloring used in the manufacturing process of an OLED microdisplay.

[0063] In this embodiment, by reducing the opening width W1 of the opening 8 and adjusting the protrusion ratio R of the ridge portion to be 0.001 or more and 0.018 or less, the mask can be effectively used as a deposition mask 1 used in manufacturing high-resolution OLED display devices.

[0064] 11 , deposition material (deposition particles) 12 from a deposition source 11 passes through the openings 8 in the deposition mask 1 and reaches the surface 10a of the deposition target substrate 10, forming a deposition film 13. When the pattern width W3 of the deposition film 13 is measured and the ratio to the opening width W1 is calculated, a protrusion ratio R at which the pattern width ratio ((pattern width W3 / opening width W1)×100(%)) is 70% or more is determined to be the present example, and a protrusion ratio R of less than 70% is determined to be a comparative example.

[0065] In the present embodiment, the opening width W1 of the opening 8 gradually narrows from the second surface 2b toward the first surface 2a. However, this is not limiting and the opening width W1 may gradually widen from the second surface 2b toward the first surface 2a. While the taper angle is not limited, the taper angle θ1 is preferably 60° or more and 120° or less, more preferably 70° or more and 110° or less, and even more preferably 80° or more and 105° or less. The sidewall surface 9 of the opening 8 is preferably tapered from the second surface 2b toward the first surface 2a. By forming the sidewall surface 9 toward the deposition source 11, i.e., from the second surface 2b toward the first surface 2a (see FIG. 11 ), the deposition particles 12 can easily pass from the deposition source 11 toward the deposition target substrate 10, thereby forming a deposition film 13 with excellent pattern dimensions.

[0066] <Regarding the manufacturing method of the deposition mask 1 according to the present embodiment> Fig. 9 is a process chart showing the manufacturing method of the deposition mask 1 according to the present embodiment. Here, the deposition mask 1 in the manufacturing process shown in Fig. 9 and Fig. 10 described later shows only the vicinity of one cell region 4, but in reality, the multiple cell regions 4 shown in Fig. 1 are formed simultaneously.

[0067] 9A, a support substrate 21 made of, for example, Si is prepared, and in FIG. 9B, a membrane 2 is formed on the surface of the support substrate 21. For example, the membrane 2 is formed of a material such as SiO ２ The layer 22 and the SiN layer 23 are laminated together.

[0068] Although there is no limitation on the diameter of the membrane 2, in this embodiment, a diameter of up to about 500 mm can be accommodated.

[0069] 9C, a protective material 24 is formed on the entire surface of the membrane 2. A mask layer 25 is also formed on the back surface of the support substrate 21. The mask layer 25 is a resist pattern. As shown in FIG. 9C, the mask layer 25 is not formed in the area of ​​the membrane 2 that will become the cell region 4.

[0070] 9D, the support substrate 21 that is not covered with the mask layer 25 is removed by dry etching. As a result, the support substrate 3 is formed on the second surface 2b of the membrane 2 except for the position of the cell region 4. Then, the mask layer 25 is removed.

[0071] 9E , a resist layer is applied from the support substrate 3 to the second surface 2b of the cell region 4, and a mask layer 26 having an opening pattern 26a is formed on the resist layer. The opening pattern 26a is a pattern for forming openings 8 in the membrane 2, and the membrane 2 exposed from the opening pattern 26a is removed by dry etching. This allows the openings 8 to be formed in the membrane 2.

[0072] 9F, the mask layer 26 and the protective material 24 are removed. This completes the deposition mask 1, which includes the membrane 2 having a plurality of openings 8 in the cell region 4 and the support substrate 3 formed on the second surface 2b side of the membrane 2. In the manufacturing method shown in FIG. 9, the openings 8 can be formed with a tapered surface having a taper angle θ1 of 90° or less.

[0073] A method for manufacturing the deposition mask 1 shown in Fig. 10 will be described. The steps of Fig. 10A and Fig. 10B shown in Fig. 10 are the same as those of Fig. 9A and Fig. 9B.

[0074] 10C, mask layers 27 and 28 are formed on both the first surface 2a of the membrane 2 and the rear surface of the support substrate 21. It is preferable that both the mask layers 27 and 28 are formed of resist.

[0075] 10C , the mask layer 28 formed on the back surface of the support substrate 21 is not formed in the cell region 4 of the membrane 2. Furthermore, a plurality of opening patterns 27a are formed in the mask layer 27 formed on the first surface 2a of the membrane 2. The opening patterns 27a allow a plurality of openings 8 to be formed in the membrane 2.

[0076] 10D, the membrane 2 exposed from the opening pattern 27a of the mask layer 27 is removed by dry etching. This allows a plurality of openings 8 to be formed in the membrane 2.

[0077] Next, the support substrate 21 that is not covered by the mask layer 28 is removed, thereby opening the cell region 4 of the membrane 2 to the second surface 2b as well. Then, the mask layers 27 and 28 are removed.

[0078] 10E, a deposition mask 1 is completed, which includes the membrane 2 having a plurality of openings 8 in the cell region 4 and the support substrate 3 formed on the second surface 2b side of the membrane 2. In the manufacturing method shown in FIG. 10, the openings 8 can be formed with an inversely tapered surface having a taper angle θ1 of 90° or more.

[0079] 9E and 10D, the conditions of the dry etching used to form the opening 8 in the membrane 2 are adjusted, for example, as follows: The etching conditions can be adjusted by the flow rates of various gases, the chamber pressure, the power of the plasma generation source, etc.

[0080] As an example, CF is used as an etching gas. ４ Gas, O ２ Using gas, CF ４ Gas: 0.1 to 100 sccm, O ２ The gas flow rate was set to 1 to 200 sccm. Various conditions were adjusted, including a platen LF of 500 to 3000 W, a coil RF of 500 to 4000 W, a chamber pressure of 1 to 10 Pa, and an etching time of several minutes. ４ Gas and O ２ Regarding the flow rate of each gas, CF ４ Gas flow rate <0 ２ This allows the protrusion dimension (which may be interpreted as the groove depth between the vertical stripes) of the number of vertical stripes (protrusions) to be reduced, and specifically, the protrusion ratio R of the protrusions 20 to the opening width W1 of the opening 8 can be appropriately adjusted to be 0.001 or more and 0.018 or less.

[0081] The fluorine compound is, for example, CF ４ , SF ６ , N.F. ３ , B.F. ３ , P.F. ５ and F ２ The rare gas may be selected from the group consisting of helium and argon, but may not be used. The protrusion dimension of the protrusion 20 can be reduced by laser hydrogen annealing or the like.

[0082] 11 , the deposition mask 1 is placed between a deposition target substrate 10 and a deposition source 11. At this time, the first surface 2a of the membrane 2 of the deposition mask 1 faces the deposition target substrate 10, and the second surface 2b of the membrane 2 faces the deposition source 11. A plurality of openings 8 are formed in the membrane 2, and, for example, the opening width is narrower on the first surface side than on the second surface side.

[0083] The deposition mask 1 is placed on a holder (not shown) of a deposition device, and the deposition mask 1 and the deposition substrate 10 can be fixed together by an electrostatic chuck. In FIG. 11 , the membrane 2 and the deposition substrate 10 are separated from each other, but they may be in contact with each other. The deposition mask 1 and the deposition substrate 10 are rotated around the axis of the holder. Deposition material (deposition particles) 12 from a deposition source 11 passes through openings 8 in the deposition mask 1 and reaches the surface 10 a of the deposition substrate 10, forming a deposition film 13.

[0084] In this embodiment, examples of electronic devices include OLED microdisplay panels, liquid crystal panels, solar cells, etc., and the present invention is particularly suited to a method for manufacturing an OLED microdisplay panel as an organic electronic device.

[0085] By using the deposition mask 1 of this embodiment, the pattern width W3 of the deposited film 13 can be ensured to be 70% or more of the opening width W1, preferably 75% or more, and more preferably 80% or more. In this way, the deposited film 13 having excellent pattern dimensions can be formed.

[0086] <Effects of Using the Vapor Deposition Mask 1 of the Present Embodiment> In the present embodiment, by specifying the protrusion ratio of the protrusions 20 in the openings 8 of the vapor deposition mask 1, it is possible to obtain high pattern dimensions for the vapor deposition film 13. Furthermore, since the amount of deposition material deposited can be reduced, the frequency of cleaning the vapor deposition mask 1 can be reduced, and quality control of the vapor deposition mask 1 can be easily performed. Furthermore, it is possible to reduce clogging of the openings 8, thereby extending the life of the vapor deposition mask 1.

[0087] Although the embodiments and modifications have been described, other embodiments may be obtained by combining the above embodiments and modifications in whole or in part.

[0088] Furthermore, the present invention is not limited to the above-described embodiments and modifications, and may be variously changed, substituted, or modified within the scope of the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way due to technological advances or other derived technologies, it may be implemented using that method. Therefore, the claims cover all embodiments that may fall within the scope of the technical idea.

[0089] An embodiment of a deposition mask having a layer structure different from that of the deposition mask 1 shown in Fig. 1 will be described. For example, as shown in Fig. 12, a deposition mask having a layer structure such as SiN or SiO ２ Alternatively, a membrane 31 such as the above may be formed, and a plurality of openings 8 may be formed in the membrane 31 in the central region where the silicon substrate 30 has been removed. The membrane is formed by CVD, but it is preferable to use SiN in view of ease of stress control.

[0090] 13 to 15 use an SOI substrate 39, but in Fig. 13, a SiN layer 45 is formed on the back side (support substrate 44 side, side facing deposition source 11) of the SOI substrate 39, in Fig. 14, the SiN layer 45 is formed on the front side (semiconductor layer 42 side, side facing deposition target substrate 10) of the SOI substrate 39, and in Fig. 15, the SiN layer 45 is formed on both the back side and front side of the SOI substrate 39. In the configuration in which the SiN layer 45 is formed on the front side (semiconductor layer 42 side) of the SOI substrate 39, an opening 8 is formed continuous with the semiconductor layer 42.

[0091] By providing the SiN layer 45, stress control of the deposition mask is facilitated and distortion, etc. can be suppressed. Furthermore, the SiN layer 45 formed on the front side of the SOI substrate 39 is preferably thinner than the SiN layer 45 formed on the back side of the SOI substrate 39. Although not limited thereto, the thickness of the SiN layer 45 formed on the front side of the SOI substrate 39 is approximately 0.05 μm to 0.5 μm, and the thickness of the SiN layer 45 formed on the back side of the SOI substrate 39 is approximately 0.05 μm to 3 μm. Because the semiconductor layer 42 is thinner than the support substrate 44 and also has numerous openings 8 formed in the semiconductor layer 42, the SiN layer 45 formed on the front side of the SOI substrate 39 is thinner than the SiN layer 45 formed on the back side of the SOI substrate 39 to achieve balanced stress control between the front side and the back side.

[0092] The opening 8 can be formed in the SOI substrate 39 by using the Bosch process, and in the SiN layer 45 by dry etching.

[0093] At least one of the support substrate 3 and the membrane 2 shown in FIG. 1 may have a polycrystalline silicon structure. Since polycrystalline silicon does not have a clear cleavage plane, it is less likely to break in the cleavage direction than single-crystal silicon, which has a cleavage plane. Although it is technically difficult to produce a large substrate from a single-crystal silicon material, using a polycrystalline silicon structure for the deposition mask 1 makes it easier to form a silicon substrate larger than a single-crystal silicon substrate. Furthermore, by making the planar shape of the deposition mask 1 polygonal (e.g., rectangular), the chamfering efficiency can be improved compared to a circular deposition mask 1, and the number of surfaces can also be increased. A large-sized silicon substrate is preferably 500 mm x 500 mm or larger.

[0094] The effects of the present invention will be explained below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0095] <Production of deposition mask samples> A plurality of deposition mask samples were produced by the production method shown in Fig. 9 or Fig. 10. At this time, the membrane was made of SiO ２In the experiment, the dry etching conditions for forming the openings in the membrane were changed in various ways, and a number of samples (Experimental Examples 1 to 30) with different protrusion dimensions of the protrusions were produced.

[0096] <SEM images of protrusions> Fig. 7A is an SEM image of the side wall surface of the opening, and Fig. 7B is a schematic diagram thereof. As shown in Fig. 7A and Fig. 7B, it was confirmed from the SEM images that multiple vertical ridges (protrusions) extending in the height direction were formed on the side wall surface.

[0097] <Deposition Conditions in Experiments> Next, the deposition material was vacuum-deposited onto a deposition substrate using Experimental Examples 1 to 6 (opening width W1 was 3 μm) shown in Table 1. Then, the pattern width W3 of the deposited film was measured with a laser microscope (model number: VKX-210 (manufactured by Keyence Corporation)), and the deposition pattern width ratio (converted to 100%) to the opening width W1 of the deposition mask opening was calculated.

[0098] At this time, the deposition amount (time) applied to the experiment was determined as the deposition condition for Experimental Example 7 and thereafter when one or more samples among Experimental Examples 1 to 6 had a deposition pattern width ratio of less than 70%.

[0099] <Evaluation Criteria> Experimental examples in which the pattern width ratio was less than 70% were evaluated as ×, experimental examples in which the pattern width ratio was 70 to 85% were evaluated as ◯, and experimental examples in which the pattern width ratio was more than 85% were evaluated as ⊚. The experimental results are shown in Table 1 below.

[0100]

[0101] As shown in Table 1, by setting the protrusion ratio, calculated as (average protrusion dimension / opening width of opening), to 0.018 or less, it was found that the pattern width ratio could be made 70% or more (evaluated as ○ or ◎), and the deposited film could be formed with a stable pattern width dimension.

[0102] Furthermore, by setting the protrusion ratio, calculated as (average protrusion dimension / opening width of opening), to 0.014 or less, it was found that the pattern width ratio could be made to exceed 85% (evaluated as ◎), and the pattern width accuracy of the vapor deposition film could be more stably formed.

[0103] The lower limit of the protrusion ratio is preferably as small as possible, and is set to 0.001 or more. Experimental examples have shown that the protrusion ratio can be set to 0.004 or more.

[0104] The average protrusion dimension of the protrusions is set to 150 nm or less, preferably 145 nm or less, and more preferably 143.5 nm or less.

[0105] The maximum protrusion dimension of the protrusions is set to 200 nm or less, preferably 185 nm or less, and more preferably 181 nm or less.

[0106] The opening width is preferably 10 μm or less, and the lower limit of the opening width is 1 μm or more, and may be 3 μm or more in accordance with experimental examples.

[0107] The "taper angles" shown in Table 1 are representative values, and it was confirmed that all experimental examples fell within a range of ±3° from each representative value.

[0108] This application is based on Japanese Patent Application No. 2024-097401, filed on June 17, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A deposition mask having a first surface and a second surface opposite to the first surface, and having a plurality of openings formed therein that penetrate between the first surface and the second surface, wherein a protrusion extending from the first surface to the second surface is formed on a side wall surface of the opening, and the protrusion ratio of the protrusion to the opening width of the opening is 0.001 or more and 0.018 or less.

2. The deposition mask according to claim 1, wherein the protrusion ratio is 0.014 or less.

3. The deposition mask according to claim 1, wherein the opening width is determined by the opening width on the first surface side, when the deposition substrate side is the first surface and the deposition source side is the second surface.

4. The deposition mask according to claim 1, wherein the average protrusion dimension of the protrusions is 150 nm or less.

5. The deposition mask according to claim 1, wherein the maximum protrusion dimension of the protrusions is 200 nm or less.

6. The deposition mask according to claim 1, wherein the opening width is 10 μm or less.

7. The deposition mask according to claim 1, characterized in that the deposition mask has a structure in which a membrane having the openings is supported on a support substrate, and the membrane has a silicon nitride film single layer structure or a silicon nitride film and silicon oxide film laminated structure.

8. The deposition mask according to claim 1, characterized in that the deposition mask is made of an SOI substrate, and a SiN layer is formed on the front side, or the back side, or both the front side and the back side, on which the opening is formed.

9. The deposition mask according to claim 1, characterized in that the deposition mask has a structure in which a membrane having the opening is supported on a support substrate, and at least one of the membrane and the support substrate has a polycrystalline silicon structure.

10. A method for manufacturing an electronic device, comprising: placing the deposition mask according to claim 1 between a substrate to be deposited and a deposition source, with the first surface facing the substrate to be deposited and the second surface facing the deposition source; and depositing a deposition material onto the surface of the substrate to be deposited through the openings.

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